How many hydrogen ions are present in `1ml` of a solution of `pH=13`?

Options

A. `10^(-16)`
B. `6.022xx10^(13)`
C. `6.022xx10^(7)`
D. `6.022xx10^(23)`

Answer

C

Explanation

`C_(H^(+))=10^(-pH) mol L^(-1)`
`= 10^(-13)(mol)/(L) (pH= 13)`
`=10^(-16)(mol)/(mL)(1 L = 1000 mL)`
i.e., `10^(-16) mol H^(+)` ions are present in every milliliter of aolution. Thus, the number of `H^(+)` ions present in 1 mL.
`=(("Moles of " H^(+))/("Ions in 1 mL"))` x (Avogadro's constant)
`=(10^(-16)(mol)/(mL))(6.022xx10^(23)(H^(+)ions)/(mol))`
`6.022xx10^(7)H^(+)` ions `mL^(-1)`